A study on nonlinear ultrasonic waves in bubbly media: One and two-dimensional numerical experiments.

Abstract

Nonlinear ultrasonic waves are studied in bubbly media, typically liquids with gas bubbles. The acoustic behavior is modeled by a differential system which couples the acoustic pressure and the nonlinear dynamic of the bubbles. The differential equations are solved by means of a numerical model that gives the acoustic pressure and bubble volume variation as time traces (SNOW-BL code) in two configurations: one and two dimensions. Results are shown for one-dimensional progressive and standing waves as well as for two-dimensional progressive waves, with or without focus. Experiments are carried out with bubbles evenly distributed or forming clouds, for example, in the pre-focal zone. [This work is part of the research project DPI2008-01429.]